Electron transport in crystalline TiO2 (rutile phase) is investigated by frequency-dependent conductivity measurements using THz time-domain spectroscopy. Transport is limited by electron-phonon coupling, resulting in a strongly temperature-dependent electron-optical phonon scattering rate, with significant anisotropy in the scattering process. The experimental findings can be described by Feynman polaron theory within the intermediate coupling regime and allow for a determination of electron mobility.

doi.org/10.1103/physrevb.69.081101
Phys. Rev. B

Hendry, E., Wang, F., Shan, J., Heinz, T. F., & Bonn, M. (2004). Electron transport in TiO2 probed by THz time-domain spectroscopy. Phys. Rev. B, 69. doi:10.1103/physrevb.69.081101